Syntheses,Molecular Structure and Thermodynamic Properties of 3‐Nitro‐1,2,4‐triazol‐5‐one Europium Complex [Eu(NTO)3(H2O)5]·5H2O

3‐Nitro‐1,2,4‐triazol‐5‐one (NTO) europium complex of [Eu(NTO)₃(H₂O)₅]·5H₂O was synthesized by mixing the aqueous solution of lithium 3‐nitro‐1,2,4‐triazol‐5‐onate and the dilute nitric acid solution of europium oxide. The title complex was characterized by elemental analysis and IR spectra. The single crystal structure was determined by a four‐circle x‐ray diffractometer. The title complex is monoclinic with space group P2₁/n and unit cell parameters of a = 1.8720(2) nm, b = 0.6548(3) nm, c = 1.9323(3) nm and β = 95.33(1)°. The coordination geometry around the europium ion is a distorted dodecahedron and there are five crystalline water molecules to form the stable structure of the crystal. From measurements of the enthalpy of solution in water at 298.15 K, the standard enthalpy of formation, lattice enthalpy and lattice energy have been determined as ‐(3798.6 ± 3.7), ?4488.4 and ?4452.4 kJ·mol^?;1, respectively.     

Two‐Photon Absorption Properties of Dehydrobenzo[12]annulenes and Hexakis(phenylethynyl)benzenes: Effect of Edge‐Linkage

Two‐photon absorption (TPA) properties of two trefoil‐shaped compounds with different edge linkages—tris(hexadehydrotribenzo[12]annulene) and tris(tetradehydrotribenzo[12]annulene)—and three asterisk‐shaped compounds having no edge‐linkage—hexakis(phenylethynyl)benzenes—are investigated experimentally by the open‐aperture Z‐scan and TPA‐induced fluorescence methods with wavelength tuneable femtosecond pulses. The compound with ethynylene edge‐linkage exhibits the most intense TPA (the maximal TPA cross section is 1300±170 GM at 572 nm where 1 GM=10^?50 cm⁴ s molecule^?1 photon^?1). The TPA activity of the compounds is primarily explained in terms of the planarity of the molecules in relation with the type of edge‐linkage.     

A Highly K+‐Selective Two‐Photon Fluorescent Probe

A highly K⁺‐selective two‐photon fluorescent probe for the in vitro monitoring of physiological K⁺ levels in the range of 1–100 mM is reported. The two‐photon excited fluorescence (TPEF) probe shows a fluorescence enhancement (FE) by a factor of about three in the presence of 160 mM K⁺, independently of one‐photon (OP, 430 nm) or two‐photon (TP, 860 nm) excitation and comparable K⁺‐induced FEs in the presence of competitive Na⁺ ions. The estimated dissociation constant (K_d) values in Na⁺‐free solutions (K_d^OP=(28±5) mM and K_d^TP=(36±6) mM ) and in combined K⁺/Na⁺ solutions (K_d^OP=(38±8) mM and K_d^TP=(46±25) mM ) reflecting the high K⁺/Na⁺ selectivity of the fluorescent probe. The TP absorption cross‐section (σ_2PA) of the TPEF probe+160 mM K⁺ is 26 GM at 860 nm. Therefore, the TPEF probe is a suitable tool for the in vitro determination of K⁺.     

Synthesis of α‐MoC1−x Nanoparticles with a Surface‐Modified SBA‐15 Hard Template: Determination of Structure–Function Relationships in Acetic Acid Deoxygenation

Surface modification of mesoporous SBA‐15 silica generated a hydrophobic environment for a molybdenum diamine (Mo‐diamine) precursor solution, enabling direct growth of isolated 1.9±0.4 nm α‐MoC_1?x nanoparticles (NPs) inside the pores of the support. The resulting NP catalysts are bifunctional, and compared to bulk α‐MoC_1?x and β‐Mo₂C, the NPs exhibit a greater acid‐site:H‐site ratio and a fraction of stronger acid sites. The greater acid‐site:H‐site ratio results in higher decarbonylation (DCO) selectivity during acetic acid hydrodeoxygenation (HDO) reactions, and the stronger acid sites lead to higher activity and ketonization (KET) selectivity at high temperatures. The hard‐templating synthetic method could be a versatile route toward carbide NPs of varying size, composition, and phase, on a range of mesoporous oxide supports.     

Synthesis,pH‐ and temperature‐induced micellization and gelation of doubly hydrophilic triblock copolymer of poly(N,N‐dimethylamino‐2‐ethylmethacrylate)‐b‐poly(ethylene glycol)‐b‐poly(N,N‐dimethylamino‐2‐ethylmethacrylate) in aqueous solutions

A doubly hydrophilic triblock copolymer of poly(N,N‐dimethylamino‐2‐ethyl methacrylate)‐b‐Poly(ethylene glycol)‐b‐poly(N,N‐dimethylamino‐2‐ethylmethacrylate) (PDMAEMA‐b‐PEG‐b‐PDMAEMA) with well‐defined structure and narrow molecular weight distribution (M_w/M_n = 1.21) was synthesized in aqueous medium via atom transfer radical polymerization (ATRP) of N,N‐dimethylamino‐2‐ethylmethacrylate (DMAEMA) initiated by the PEG macroinitiator. The macroinitiator and triblock copolymer were characterized with ¹H NMR and gel permeation chromatography (GPC). Fluorescence spectroscopy, dynamic light scattering (DSL), transmittance measurement, and rheological characterization were applied to investigate pH‐ and temperature‐induced micellization in the dilute solution of 1 mg/mL when pH > 13 and gelation in the concentrated solution of 25 wt % at pH = 14 and temperatures beyond 80 °C. The unimer of R_h = 3.7 ± 0.8 nm coexisted with micelle of R_h = 45.6 ± 6.5 nm at pH 14. Phase separation occurred in dilute aqueous solution of the triblock copolymer of 1 mg/mL at about 50 °C. Large aggregates with R_h = 300–450 nm were formed after phase separation, which became even larger as R_h = 750–1000 nm with increasing temperature. The gelation temperature determined by rheology measurement was about 80 °C at pH 14 for the 25 wt % aqueous solution of the triblock copolymer. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5869–5878, 2008     

N-(4-甲基苯甲酰氨基) N’-[5-(2-三氟甲基苯基)-2-呋喃甲酰硫脲的合成、晶体结构测定与生物活性测定

本文首次合成标题化合物N-(4-甲基苯甲酰氨基)-N’-[5-(2-三氟甲基苯基)-2-呋喃甲酰硫脲。化合物(C21H16F3N3O3S, Mr = 447.43)单晶经测定为单斜晶体,空间群为P -1。在晶体中,存在一些分子内和分子间的相互作用,分子间还有C—H···π 的相互作用,这可能导致晶体更稳定的原因。目标产物的结构经IR, H NMR和元素分析测定确证。初步生物活性测试表明,部分化合物对棉花枯萎病、黄瓜灰霉病、苹果轮纹病和棉花炭疽病有较好的选择性杀菌活性;部分目标化合物有较好的除草活性。     

Gas‐phase ozonolysis: Rate coefficients for a series of terpenes and rate coefficients and OH yields for 2‐methyl‐2‐butene and 2,3‐dimethyl‐2‐butene

The kinetics of the gas‐phase reactions of O₃ with a series of selected terpenes has been investigated under flow‐tube conditions at a pressure of 100 mbar synthetic air at 295 ± 0.5 K. In the presence of a large excess of m‐xylene as an OH radical scavenger, rate coefficients k(O₃+terpene) were obtained with a relative rate technique, (unit: cm³ molecule^?1 s^?1, errors represent 2σ): α‐pinene: (1.1 ± 0.2) × 10^?16, ³Δ‐carene: (5.9 ± 1.0) × 10^?17, limonene: (2.5 ± 0.3) × 10^?16, myrcene: (4.8 ± 0.6) × 10^?16, trans‐ocimene: (5.5 ± 0.8) × 10^?16, terpinolene: (1.6 ± 0.4) × 10^?15 and α‐terpinene: (1.5 ± 0.4) × 10^?14. Absolute rate coefficients for the reaction of O₃ with the used reference substances (2‐methyl‐2‐butene and 2,3‐dimethyl‐2‐butene) were measured in a stopped‐flow system at a pressure of 500 mbar synthetic air at 295 ± 2 K using FT‐IR spectroscopy, (unit: cm³ molecule^?1 s^?1, errors represent 2σ ): 2‐methyl‐2‐butene: (4.1 ± 0.5) × 10^?16 and 2,3‐dimethyl‐2‐butene: (1.0 ± 0.2) × 10^?15. In addition, OH radical yields were found to be 0.47 ± 0.04 for 2‐methyl‐2‐butene and 0.77 ± 0.04 for 2,3‐dimethyl‐2‐butene. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 394–403, 2002     

Kinetic study and UV–Vis spectra of 1:2 complexation of free base para‐substituted meso‐tetraphenylporphyrins with trimethylsilyl chloride

The UV–Vis spectra for 1:2 complexation of four different para‐substituted meso‐tetraphenylporphyrin (H₂t(4‐X)pp) and meso‐tetraphenylporphyrins (H₂tpp) with trimethylsilyl chloride (TMSC) displayed large and different redshifts (28–32.4 nm) of Soret and (15–41.7 nm) Q_(0‐0) bands, whereas 1:2 complexation of the less flexible tetramesitylporphyrin (H₂tmp) with TMSC led to rather small redshift (24.8 nm) of the Soret band and blueshift (−7.4 nm) of the Q_(0‐0) band. The varying spectral behavior for the porphyrins complexation seems to essentially reflect the different extent of π‐interactions between the meso‐aryl groups and the presumably saddled porphyrin macrocycle, through their relative coplanarity. The observed order of the rate constants for the complexation of various para‐substituted porphyrins, H₂t(4‐OCH₃)pp (9.27 ± 0.03) × 10⁻³ > H₂t(4‐CH₃)pp (6.68 ± 0.05) × 10⁻³ > H₂tpp (3.2 ± 0.05) × 10⁻³ > H₂t(4‐Cl)pp (8.36 ± 0.06) × 10⁻⁴, clearly demonstrated a higher reaction rate for the porphyrins containing para‐substituents with stronger electron donor ability. The calculated order for porphyrins (0.9 ± 0.1) and for TMSC (1.0 ± 0.1) suggests rate = K[Por][TMSC] for the complexation. Attempts were made to explain the absence of spectral evidence for the presence of an intermediate 1:1 (TMSC) Por adduct in terms of its high reactivity and/or relative instability. © 2007 Wiley Periodicals, Inc. 39: 231–235, 2007     

Kinetics of the gas‐phase reactions of Cl atom with selected C2–C5 unsaturated hydrocarbons at 283 < T < 323 K

The reaction of Cl atoms with a series of C₂–C₅ unsaturated hydrocarbons has been investigated at atmospheric pressure of 760 Torr over the temperature range 283–323 K in air and N₂ diluents. The decay of the hydrocarbons was followed using a gas chromatograph with a flame ionization detector (GC‐FID), and the kinetic constants were determined using a relative rate technique with n‐hexane as a reference compound. The Cl atoms were generated by UV photolysis (λ ≥ 300 nm) of Cl₂ molecules. The following absolute rate constants (in units of 10⁻¹¹ cm³ molecule⁻¹ s⁻¹, with errors representing ±2σ) for the reaction at 295 ± 2 K have been derived from the relative rate constants combined to the value 34.5 × 10⁻¹¹ cm³ molecule⁻¹ s⁻¹ for the Cl + n‐hexane reaction: ethene (9.3 ± 0.6), propyne (22.1 ± 0.3), propene (27.6 ± 0.6), 1‐butene (35.2 ± 0.7), and 1‐pentene (48.3 ± 0.8). The temperature dependence of the reactions can be expressed as simple Arrhenius expressions (in units of 10⁻¹¹ cm³ molecule⁻¹ s⁻¹): k_ethene = (0.39 ± 0.22) × 10⁻¹¹ exp{(226 ± 42)/T}, k_propyne = (4.1 ± 2.5) × 10⁻¹¹ exp{(118 ± 45)/T}, k_propene = (1.6 ± 1.8) × 10⁻¹¹ exp{(203 ± 79)/T}, k_1‐butene = (1.1 ± 1.3) × 10⁻¹¹ exp{(245 ± 90)/T}, and k_1‐pentene = (4.0 ± 2.2) × 10⁻¹¹ exp{(423 ± 68)/T}. The applicability of our results to tropospheric chemistry is discussed. © 2000 John Wiley & Sons, Inc. Int J Chem Kinet 32: 478–484, 2000     

Dithienobenzothiadiazole‐Based Conjugated Polymer: Processing Solvent‐Relied Interchain Aggregation and Device Performances in Field‐Effect Transistors and Polymer Solar Cells

DTfBT‐Th₃, a new conjugated polymer based on dithienobenzothiadiazole and terthiophene, possesses a bandgap of ≈1.86 eV and a HOMO level of −5.27 eV. Due to strong interchain aggregation, DTfBT‐Th₃ can not be well dissolved in chloro­benzene (CB) and o‐dichlorobenzene (DCB) at room temperature (RT), but the polymer can be processed from hot CB and DCB solutions of ≈100 °C. In CB, with a lower solvation ability, a certain polymer chain aggregation can be preserved, even in hot solution. DTfBT‐Th₃ displays a field‐effect hole mobility of 0.55 cm² V⁻¹ s⁻¹ when fabricated from hot CB solution, which is higher than that of the device processed from hot DCB (0.16 cm² V⁻¹ s⁻¹). In DTfBT‐Th₃‐based polymer solar cells, a good power conversion efficiency from 5.37% to 6.67% can be achieved with 150−300 nm thick active layers casted from hot CB solution, while the highest efficiency for hot DCB‐processed solar cells is only 5.07%. The results demonstrate that using a solvent with a lower solvation ability, as a “wet control” process, is beneficial to preserve strong interchain aggregation of a conjugated polymer during solution processing, showing great potential to improve its performances in optoelectronic devices.

     

Adsorption behaviour of a CdII–triazole MOF for butan‐2‐one in a single‐crystal‐to‐single‐crystal (SCSC) fashion: the role of hydrogen bonding and C—H…π interactions

The adsorption behaviour of the Cd^II–MOF {[Cd(L)₂(ClO₄)₂]·H₂O ( 1 ), where L is 4‐amino‐3,5‐bis[3‐(pyridin‐4‐yl)phenyl]‐1,2,4‐triazole, for butan‐2‐one was investigated in a single‐crystal‐to‐single‐crystal (SCSC) fashion. A new host–guest system that encapsulated butan‐2‐one molecules, namely poly[[bis{μ₃‐4‐amino‐3,5‐bis[3‐(pyridin‐4‐yl)phenyl]‐1,2,4‐triazole}cadmium(II)] bis(perchlorate) butanone sesquisolvate], {[Cd(C₂₄H₁₈N₆)₂](ClO₄)₂·1.5C₄H₈O}_n, denoted C₄H₈O@Cd‐MOF ( 2 ), was obtained via an SCSC transformation. MOF 2 crystallizes in the tetragonal space group P4₃2₁2. The specific binding sites for butan‐2‐one in the host were determined by single‐crystal X‐ray diffraction studies. N—H…O and C—H…O hydrogen‐bonding interactions and C—H…π interactions between the framework, ClO₄^? anions and guest molecules co‐operatively bind 1.5 butan‐2‐one molecules within the channels. The adsorption behaviour was further evidenced by ¹H NMR, IR, TGA and powder X‐ray diffraction experiments, which are consistent with the single‐crystal X‐ray analysis. A ¹H NMR experiment demonstrates that the supramolecular interactions between the framework, ClO₄^? anions and guest molecules in MOF 2 lead to a high butan‐2‐one uptake in the channel.     

Synthesis of 1‐Methyl‐3‐aryl‐substituted Titanocene and Zirconocene Dichlorides and Crystal Structure of Bis[η5‐1‐methyl‐3‐(α, α‐dimethylbenzyl) cyclopentadienyl] titanium Dichloride

The syntheses of a series of l‐methyl‐3‐aryl‐substituted titanocene and zirconocene dichlorides are reported. These complexes are synthesized by the reaction of 2‐ and 3‐methyl‐6, 6‐dimethylfulvenes (1:4) with aryllithium, followed by the reaction with TiCl₄·2THF, ZrCl₄ and (CpTiCl₂)₂O respectively, to give complexes 1–5. The complex [η⁵‐1‐methyl‐3‐(α, α‐dimethylbenzyl) cyclopentadienyl] titanium dichloride has been studied by X‐ray diffraction. The red crystal of this complex is monoclinic, space group P2_t/C with unit cell parameters: a =6.973(6) × 10^?1 nm, b =36.91(2) × 10^?1 nm, c = 10.063(4) × 10^?1 nm, α=β= γ = 93.35(5)°, V = 2584(5) × 10^?3 nm³ and Z = 4. Refinement for 1004 observed reflections gives the final R of 0.088. There are four independent molecules per unit cell.     

Kinetics of the mercury(II)‐catalyzed substitution of coordinated cyanide ion in hexacyanoruthenate(II) by nitroso‐R‐salt

The kinetics and mechanism of Hg²⁺‐catalyzed substitution of cyanide ion in an octahedral hexacyanoruthenate(II) complex by nitroso‐R‐salt have been studied spectrophotometrically at 525 nm (λ_max of the purple‐red–colored complex). The reaction conditions were: temperature = 45.0 ± 0.1°C, pH = 7.00 ± 0.02, and ionic strength (I) = 0.1 M (KCl). The reaction exhibited a first‐order dependence on [nitroso‐R‐salt] and a variable order dependence on [Ru(CN)₆^4?]. The initial rates were obtained from slopes of absorbance versus time plots. The rate of reaction was found to initially increase linearly with [nitroso‐R‐salt], and finally decrease at [nitroso‐R‐salt] = 3.50 × 10^?4 M. The effects of variation of pH, ionic strength, concentration of catalyst, and temperature on the reaction rate were also studied and explained in detail. The values of k₂ and activation parameters for catalyzed reaction were found to be 7.68 × 10^?4 s^?1 and E_a = 49.56 ± 0.091 kJ mol^?1, ΔH^≠ = 46.91 ± 0.036 kJ mol^?1, ΔS^≠ = ?234.13 ± 1.12 J K^?1 mol^?1, respectively. These activation parameters along with other experimental observations supported the solvent assisted interchange dissociative (I_d) mechanism for the reaction. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 41: 215–226, 2009     

Co‐crystals of 3‐deoxy‐3‐fluoro‐α‐d‐glucopyranose and 3‐deoxy‐3‐fluoro‐β‐d‐glucopyranose

3‐Deoxy‐3‐fluoro‐d ‐glucopyranose crystallizes from acetone to give a unit cell containing two crystallographically independent molecules. One of these molecules (at site A) is structurally homogeneous and corresponds to 3‐deoxy‐3‐fluoro‐β‐d ‐glucopyranose, C₆H₁₁FO₅, (I). The second molecule (at site B) is structurally heterogeneous and corresponds to a mixture of (I) and 3‐deoxy‐3‐fluoro‐α‐d ‐glucopyranose, (II); treatment of the diffraction data using partial‐occupancy oxygen at the anomeric center gave a high‐quality packing model with an occupancy ratio of 0.84:0.16 for (II):(I) at site B. The mixture of α‐ and β‐anomers at site B appears to be accommodated in the lattice because hydrogen‐bonding partners are present to hydrogen bond to the anomeric OH group in either an axial or equatorial orientation. Cremer–Pople analysis of (I) and (II) shows the pyranosyl ring of (II) to be slightly more distorted than that of (I) [θ_(I) = 3.85 (15)° and θ_(II) = 6.35 (16)°], but the general direction of distortion is similar in both structures [ϕ_(I) = 67 (2)° (B_C1,C4) and ϕ_(II) = 26.0 (15)° (^C3TB_C1); B = boat conformation and TB = twist‐boat conformation]. The exocyclic hydroxymethyl (–CH₂OH) conformation is gg (gauche–gauche) (H5 anti to O6) in both (I) and (II). Structural comparisons of (I) and (II) to related unsubstituted, deoxy and fluorine‐substituted monosaccharides show that the gluco ring can assume a wide range of distorted chair structures in the crystalline state depending on ring substitution patterns.     

Polymeric potassium di­aqua­hexa‐μ‐cyano‐holmium(III)­ruthenium(II) dihydrate

The crystal structure of the title bimetallic cyanide‐bridged complex, {K[HoRu(CN)₆(H₂O)₂]·2H₂O}_n, was determined by means of single‐crystal X‐ray diffraction techniques. The coordination about the central holmium(III) ion is eightfold in a square‐antiprismatic arrangement, while the ruthenium(II) ion is octahedrally coordinated. Channels permeating the crystal lattice contain the potassium cations and two zeolitic water mol­ecules. The Ho^III and K atoms lie at sites with mm symmetry and the Ru atom is at a site with 2/m symmetry.     

Polymorphism of mer‐μ‐oxalato‐bis[chloridotripyridinecobalt(II)] pyridine disolvate

Single crystals of a triclinic polymorphic form of mer‐μ‐oxalato‐bis[chloridotripyridinecobalt(II)] pyridine disolvate, [Co₂(C₂O₄)Cl₂(C₅H₅N)₆]·2C₅H₅N, have been prepared by solvothermal methods. The structure and geometric parameters strongly resemble those of the previously reported monoclinic polymorph [Bolte (2006). Acta Cryst. E 62 , m597–m598]. In both polymorphic forms, the dinuclear complex molecules are located on a crystallographic centre of inversion, with the Co^II cations in a distorted octahedral environment consisting of a chloride ligand, three pyridine ligands and a chelating bis‐bidentate oxalate ligand. This last serves as a bridging ligand between two Co^II cations. The polymorphs differ in the mutual orientation of their pyridine ligands in the dinuclear molecules and in their intermolecular connectivity. In the triclinic polymorph, C—H...O, C—H...Cl, C—H...π and π–π interactions link the dinuclear molecules into a three‐dimensional structure. Pyridine solvent molecules are attached to this structure via weak interactions.     

Rate constants for the reactions of OH radicals and Cl atoms with Di‐n‐Propyl ether and Di‐n‐Butyl ether and their deuterated analogs

Using relative rate methods, rate constants for the gas‐phase reactions of OH radicals and Cl atoms with di‐n‐propyl ether, di‐n‐propyl ether‐d₁₄, di‐n‐butyl ether and di‐n‐butyl ether‐d₁₈ have been measured at 296 ± 2 K and atmospheric pressure of air. The rate constants obtained (in cm³ molecule⁻¹ s⁻¹ units) were: OH radical reactions, di‐n‐propyl ether, (2.18 ± 0.17) × 10⁻¹¹; di‐n‐propyl ether‐d₁₄, (1.13 ± 0.06) × 10⁻¹¹; di‐n‐butyl ether, (3.30 ± 0.25) × 10⁻¹¹; and di‐n‐butyl ether‐d₁₈, (1.49 ± 0.12) × 10⁻¹¹; Cl atom reactions, di‐n‐propyl ether, (3.83 ± 0.05) × 10⁻¹⁰; di‐n‐propyl ether‐d₁₄, (2.84 ± 0.31) × 10⁻¹⁰; di‐n‐butyl ether, (5.15 ± 0.05) × 10⁻¹⁰; and di‐n‐butyl ether‐d₁₈, (4.03 ± 0.06) × 10⁻¹⁰. The rate constants for the di‐n‐propyl ether and di‐n‐butyl ether reactions are in agreement with literature data, and the deuterium isotope effects are consistent with H‐atom abstraction being the rate‐determining steps for both the OH radical and Cl atom reactions. © 1999 John Wiley & Sons, Inc. Int J Chem Kinet 31: 425–431, 1999     

Rate constants for the gas‐phase reactions of chlorine atoms with 1,4‐cyclohexadiene and 1,5‐cyclooctadiene at 298 K

Rate constants for the reactions of Cl atoms with two cyclic dienes, 1,4‐cyclohexadiene and 1,5‐cyclooctadiene, have been determined, at 298 K and 800 Torr of N₂, using the relative rate method, with n‐hexane and 1‐butene as reference molecules. The concentrations of the organics are followed by gas chromatographic analysis. The ratios of the rate constants of reactions of Cl atoms with 1,4‐cyclohexadiene and 1,5‐cyclooctadiene to that with n‐hexane are measured to be 1.29 ± 0.06 and 2.19 ± 0.32, respectively. The corresponding ratios with respect to 1‐butene are 1.50 ± 0.16 and 2.36 ± 0.38. The absolute values of the rate constants of the reaction of Cl atom with n‐hexane and 1‐butene are considered as (3.15 ± 0.40) × 10^?10 and (3.21 ± 0.40) × 10^{? 10} cm³ molecule^?1s^?1, respectively. With these, the calculated values are k(Cl + 1,4‐cyclohexadiene) = (4.06 ± 0.55) × 10^?10 and k(Cl + 1,5‐cyclooctadiene) = (6.90 ± 1.33) × 10^?10 cm³ molecule^?1 s^?1 with respect to n‐hexane. The rate constants determined with respect to 1‐butene are marginally higher, k(Cl + 1,4‐cyclohexadiene) = (4.82 ± 0.80) × 10^{? 10} and k(Cl + 1,5‐cyclooctadiene) = (7.58 ± 1.55) × 10^{? 10} cm³ molecule^?1 s^?1. The experiments for each molecule were repeated three to five times, and the slopes and the rate constants given above are the average values of these measurements, with 2σ as the quoted error, including the error in the reference rate constant. The relative rate ratios of 1,4‐cyclohexadiene with both the reference molecules are found to be higher in the presence of oxygen, and a marginal increase is observed in the case of 1,5‐cyclooctadiene. Benzene is identified as one major product in the case of 1,4‐cyclohexadiene. Considering that the cyclohexadienyl radical, a product of the hydrogen abstraction reaction, is quantitatively converted to benzene in the presence of oxygen, the fraction of Cl atoms that reacts by abstraction is estimated to be 0.30 ± 0.04. The atmospheric implications of the results are discussed. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 431–440, 2011     

A Novel Three‐Dimensional Copper(II) 1,2‐Ethylenediphosphonate Framework with Channel‐like Voids

Turquoise monoclinic single crystals of the novel three‐dimensional Cu₂[μ₈‐O₃P(CH₂)₂PO₃] · 3.2H₂O coordination polymer were prepared using the silica gel method. Space group C2/m (no. 12) with a = 1483.6(2), b = 668.44(8), c = 436.30(6) pm, β = 93.28(2)°. The Cu²⁺ cation is coordinated by four oxygen atoms stemming from the 1,2‐ethylenediphosphonate dianions in a square planar manner and two water molecules in the axial positions. The connection between the Cu²⁺ cations and the [CPO₃] units from the 1,2‐ethylenediphosphonate dianions leads to layers parallel to (100), which are linked by the ethylene groups to a three‐dimensional framework with channel‐like voids. The channel‐like voids accommodate water molecules not bound to Cu²⁺ and extend parallel to [001] with an opening of about 550 pm × 260 pm. Magnetic measurements reveal an antiferromagnetic behavior due to a superexchange coupling between Cu²⁺ ions through an oxygen bridge. The UV/Vis spectrum reveals three d–d transition bands at 694, 774, and 918 nm. The compound can be fully dehydrated by thermal treatment and rehydrated by storage in ambient air.